Author: Joely Kaufman, MD FAAD
Since the advent of fractional resurfacing in 2004, the popularity of laser resurfacing has increased dramatically. Classical laser resurfacing, used in the past, involved removing the top layers of the skin (the epidermis and parts of the dermis) in the same treatment. These lasers included the Carbon dioxide (CO2) and erbium yag (Er:Yag) devices. The entire surface area of the skin was treated with each session of classical resurfacing, requiring weeks to heal and sometimes even longer. Many patients had residual redness of the skin that could persist for months. Late complications of these classical procedures also included discoloration of the treated skin, including lightening or darkening from the normal skin color. The results of these classical laser resurfacing procedures could be incredibly positive, with tightening of the skin and a major improvement in wrinkles, but the procedure was often fraught with complications. Because of these side effects, many physicians opted not to perform these procedures in their office and the search for a safer way to treat wrinkles began.
New lasers were then introduced to the market (non- fractional, non- ablative) that did not remove any skin but instead heated the deeper layer (dermis) of the skin while maintaining normal temperatures in the superficial layer (epidermis). By heating the dermis, these lasers stimulated your skin to produce new collagen and therefore improve the appearance of the treated area. The treatments were safe, but were painful and results were modest at best. These soon feel out of favor by most.
In 2004 the concept of fractional resurfacing was introduced to the literature by a team of dermatologists at Harvard University. The idea was to apply tiny microscopic injuries to the skin with laser to induce collagen production, resurface the skin, while decreasing the chance for side effects. These lasers apply microscopic spots of heat onto the skin that are separated from each other. Surrounding each spot is healthy intact skin. As a result, one is only treating a “fraction” of the total skin in a single session, hence the term fractional. The healthy untreated portions of skin help heal the adjacent treated spots allowing for effective resurfacing without many of the complications of classical resurfacing. Today, most cosmetic laser surgeons use fractional resurfacing devices to treat numerous skin conditions, including wrinkles, abnormal pigmentation and scars.
There are 2 types of fractional resurfacing lasers- ablative and non-ablative. Ablative lasers include the CO2, Er:Yag and yttrium scandium gallium garnet (YSGG) devices. Because these lasers have wavelengths that are absorbed well by the water in skin cells, they vaporize the tissue, they leave a microscopic open wound for a few days. Fractional Ablative lasers are therefore more "aggressive" in most cases, when compared to non-ablative fractional devices. Non-ablative lasers, including the original Fraxel re:store™ device, emit wavelengths that are only moderately well absorbed by water and result in a different type of skin injury. These microscopic spots cause coagulation of tissue, leaving a closed wound. Healing with the non-ablative fractional resurfacing devices is quick- sometimes in the order of hours to days. The following section will focus on non-ablative fractional resurfacing lasers.
Fractional non-ablative resurfacing (NAFR) devices are versatile laser systems cleared by the FDA for several indications. NAFR is achieved by using laser light of a wavelength that is only modestly absorbed by the water in the skin. The light heats the water in the skin, resulting in a micro-wound. This micro-wound is termed a microthermal treatment zone (MTZ). The microwound undergoes the normal healing process resulting in turnover of old tissue and regeneration of new collagen and elastic tissue. The depth and width of each MTZ can be controlled by adjusting the laser energy. The number of MTZs per area can also be adjusted depending on the desired treatment. For example, for the treatment of deep wrinkles or scars, deeper MTZs would be used. For the treatment of more superficial conditions, such as sun freckling, more superficial settings can be used. The microwounds heal quickly with the aid of the normal, untreated skin that is surrounding each MTZ. Healing time depends on the size and even more importantly, the number of MTZs per area of skin. With light treatments, patients heal within hours. With more aggressive treatments, patients may be swollen and red for a few days. After the redness resolves, most patients experience ‘bronzing’. This bronzing occurs as the treated zones have yet to be shed from the skin, which occurs typically somewhere between days 4-7. In most cases of NAFR, patients can go back to normal activity in one to three days. Off face areas, such as the hands, neck and chest, typically take longer to completely heal.
There are several NAFR devices on the market. All emit wavelengths absorbed by water. The skin has many structures that contain water, and hence the versatility of the lasers with water as their target. The NAFR devices as a group have been cleared by the FDA for treatment of wrinkles, acne scars, surgical scars, actinic keratoses (precancers of the skin), melasma (patches of abnormal dark pigmentation), and pigmented lesions (sunspots). Success with scars and fine lines and abnormal pigmentation with NAFR is real and impressive. Deeper wrinkles do not respond as well to NAFR, even with repeated treatments. The treatment of melasma with any laser or light device is controversial, and in most cases only used as a laser resort. Melasma can worsen with any laser treatment, so consult with an experienced physician before opting for this treatment. Case reports of using NAFR on other conditions, including residual hemangiomas, nevus of Ota, poikiloderma of Civatte, enlarged pores, and even hypopigmentation have been published. These treatments are considered ‘off label’, but can be performed at the physicians discretion.
NAFR procedures are performed in the office setting using little more than topical anesthesia. There typically is some discomfort during the procedure, but little more than a feeling of heat. Some describe it as hot and prickly. Some devices are more painful than others, but all are tolerable. Depending on the size of the area being treated, treatments can take anywhere from 5-30 minutes time. After the procedure, the skin feels warm, like a sunburn, with this sensation resolving within the hour. I have never had to administer narcotics post-operatively for any NAFR patient. Applying cool compresses or ice to the area, relieves the feeling immediately, and can be used to control pain as well as swelling.
Multiple sessions with NAFR are needed for optimal results. The exact number of sessions necessary will depend on the aggressiveness of the treatments and on the condition being treated. Typically 3-5 sessions are recommended for the best outcome. The interval between sessions will also depend on the condition being treated and your skin type. Longer times between sessions (4-6 weeks) are used for darker skin patients, those at risk for pigmentation, and sensitive areas such as the chest or neck. Short intervals, of as short as 2 weeks can be used in fair skin patients.
NAFR is typically a very safe resurfacing procedure with minimal side effects. Despite this, there are some complications that can occur.
Expected side effects include a few days of redness and possible swelling. Bronzing and peeling several days post-procedure are also common, especially with the first treatment. An acne-like eruption has also been reported after NAFR and is temporary. NAFR can also activate a dormant Herpes infection, especially in those who are prone to ‘cold sores’. Be sure to advise your physician if you have a history of cold sores. Post-inflammatory hyperpigmentation- darkening of the skin as a result of the treatment itself- is the most severe of the side effects of NAFR. Those with a history of abnormal pigmentation, melasma, or darker skin types may be especially prone to this complication. In some cases, this pigmentation can be long lasting. Though all skin types can be treated with NAFR, care must be taken to those at risk for pigmentation, including adjustment of the laser settings and intervals. Severe side effects such as permanent scarring have not been reported with the NAFR devices.